Two congruent triangles can be arranged to compose a parallelogram
I can explain how two congruent triangles can arranged to compose a parallelogram.
Two congruent triangles can be arranged to compose a parallelogram
I can explain how two congruent triangles can arranged to compose a parallelogram.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- The area of a triangle is equal to half the area of the parallelogram you create from 2 congruent triangles.
- Any parallelogram can be decomposed into two congruent triangles.
Keywords
Congruent - If one shape can fit exactly on top of another using rotation, reflection or translation, then the shapes are congruent.
Parallelogram - A parallelogram is a quadrilateral with two pairs of parallel and equal sides.
Common misconception
If pupils do not cut a parallelogram from vertex to opposite vertex, they will end up with either two non-congruent shapes or two congruent quadrilaterals.
Modelling is key and this is a useful time to revisit the concept of a shape's diagonal, that is, a line connecting vertex to a non-adjacent vertex.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Three equal sides.
Two equal sides and one different.
No equal sides.
One pair of perpendicular sides.
Exit quiz
6 Questions
